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Titel |
Landslide observation and volume estimation in central Georgia based on L-band InSAR |
VerfasserIn |
E. Nikolaeva, T. R. Walter, M. Shirzaei, J. Zschau |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1561-8633
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Digitales Dokument |
URL |
Erschienen |
In: Natural Hazards and Earth System Sciences ; 14, no. 3 ; Nr. 14, no. 3 (2014-03-25), S.675-688 |
Datensatznummer |
250118340
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Publikation (Nr.) |
copernicus.org/nhess-14-675-2014.pdf |
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Zusammenfassung |
The republic of Georgia is a mountainous and tectonically active area that is
vulnerable to landslides. Because landslides are one of the most devastating
natural hazards, their detection and monitoring is of great importance. In
this study we report on a previously unknown landslide in central Georgia
near the town of Sachkhere. We used a set of Advanced Land Observation
Satellite (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR)
data to generate displacement maps using interferometric synthetic aperture
radar (InSAR). We detected a sliding zone of dimensions 2 km north–south by
0.6 km east–west that threatens four villages. We estimated surface
displacement of up to ∼30 cm/yr over the sliding body in the satellite
line-of-sight (LOS) direction, with the largest displacement occurring after
a local tectonic earthquake. We mapped the morphology of the landslide mass
by aerial photography and field surveying. We found a complex set of
interacting processes, including surface fracturing, shear and normal faults
at both the headwall and the sides of the landslide, local landslide velocity
changes, earthquake-induced velocity peaks, and loss in toe support due to
mining activity. Important implications that are applicable elsewhere can be
drawn from this study of coupled processes.
We used inverse dislocation modelling to find a possible dislocation plane
resembling the landslide basal décollement, and we used that plane to
calculate the volume of the landslide. The results suggest a décollement at
∼120 m depth, dipping at ∼10° sub-parallel to the
surface, which is indicative of a translational-type landslide. |
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